Create and export anonymous classes

Factory.java

package com.gamasoft.memoryReferences;

import java.util.Observable;

public class Factory {

    public Runnable createRunnable() {

        return new Runnable() {
            @Override
            public void run() {
                System.out.println("run");
            }
        };

    }

    static public Runnable createStaticRunnable() {

        return new Runnable() {
            @Override
            public void run() {
                System.out.println("run");
            }
        };

    }

}

Verify the presence of inner field with this test

`
package com.gamasoft.memoryReferences;
import org.junit.Test;
import java.lang.reflect.Field;
import static org.junit.Assert.*;

public class FactoryTest {

@Test
public void instanceFactory() throws NoSuchFieldException, IllegalAccessException {
    Factory myFactory = new Factory();

    Runnable r = myFactory.createRunnable();

    Field field = r.getClass().getDeclaredField("this$0");
    field.setAccessible(true);
    System.out.println("segret field: " + field.get(r).getClass());
}

@Test
public void staticFactory() throws NoSuchFieldException, IllegalAccessException {

    Runnable r = Factory.createStaticRunnable();

    Field field = r.getClass().getDeclaredField("this$0");
    field.setAccessible(true);
    System.out.println("static segret field: " + field.get(r).getClass());
}

}
`